Ice-making apparatus

ABSTRACT

An ice-making apparatus comprises a tube of high thermal conductivity material surrounded by a jacket and enclosing successive rings or collars of low thermal conductivity and high thermal conductivity materials alternatively. Water flows through the tube and the jacket forms the evaporator of a refrigeration system. Ice blocks are thereby formed within the high thermal conductivity rings and are subsequently released by disconnecting the jacket from the refrigeration system and flushing the jacket with a hot gas supply, whereupon the released blocks are expelled by the water flow and are collected on a grid near one end of the tube. After expulsion of the blocks the cycle is repeated by reconnecting the jacket to the refrigeration system. Suitable materials for the rings are polypropylene and copper.

United States Patent [191 Karas ICE-MAKING APPARATUS [76] Inventor: JohnTadeusz Karas, 3 Frogmore Grove, Blackwater, Camberley, Surrey, England22 Filed: Sept. 20, 1972 21 App]. No.1 290,467

[52] US. Cl. 62/348, 62/352 Primary Examiner-William E. Wayner'Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [451 Apr. 16, 1974 [57] ABSTRACT An ice-making apparatus comprises a tube of high thermalconductivity material surrounded by a jacket and enclosing successiverings or collars of low thermal conductivity and high thermalconductivity mate rials alternatively. Water flows through the tube andthe jacket forms the evaporator of a refrigeration system. Ice blocksare thereby formed within the high thermal conductivity rings and aresubsequently released by disconnecting the jacket from the refrigerationsystem and flushing the jacket with a hot gas sup ply, whereupon thereleased blocks are expelled by the water flow and are collected on agrid near one end of the tube. After expulsion of the blocks the cycleis repeated by reconnecting the jacket to the refrigeration system.Suitable materials for the rings are polypropylene and copper.

8 Claims, 1 Drawing Figure I PATENTEDAPR 161974 ICE-MAKING APPARATUSBACKGROUND OF THE INVENTION This invention relates to ice-makingapparatus. More specifically, it relates to such apparatus whichincludes an ice-making container from which the heat is extractednonuniformly so that separate or easily separable blocks of ice areformed.

The object of the invention is to provide an improved form of ice-makingapparatus which is more efficient and reliable than hitherto existingapparatus for producing ice blocks of a size suitable for adding todrinks.

SUMMARY OF THE INVENTION An ice-making apparatus in accordance with theinvention comprises an open-ended tube within a jacket, the tubehavingtherein successive spaced-apart heat conductive segments, meansfor directing a flow of .with provision for supplying water to one end,the ice being delivered at the other end. Heat is extracted from thewater in the tube by refrigerator evaporator tubing coiled around theice-making tube. The term evaporator is to be understood to mean part ofarefrigeration system which extracts heat from liquids, air or solids,by restricting condensed refrigeration gases through very fine orifices.This causes the condensed gas to expand at the end of restriction andconsequently cools the required matter. With this arrangement, thenonuniform heat extraction may be achieved by interrupting the coil atintervals so that the coil sections are interconnected by a-straightlength of the tubing spaced from the ice-making tube. Although thisconstruction has been found-to .bequiteeffective, it is preferred forease of production and cost reasons to use an arrangement in which theevaporator is formed by a. tubular jacketplaced and sealed around a tubeof highly conductive metal, and inside which high conductive, andnon-conductive collars or rings are placed in alternative order alongitslength, forming a common surface of cylindrical shape.

With both such arrangements heat is extracted only through spaced-apartconductive regions or segments of the tube, thus allowing ice-blocks tobe formed at intervals. It is desirable for the water to be continuouslyre-circulated through the tube as this gives clearer ice.

lf re-circulation is affected by a low pressure pump the flow decreasesas the ice is formed on the walls of the tube and provision is made forreleasing the ice, e.g. by flushing the evaporatorwith hot gases fromthe condenser, approximately at the time the flow of water stops.

The discharge end of the tube is preferably placed bya grid or the likeperforate structure which passes the water from the tube forre-circulation, e.g. into a header tank, but catches the ice blocks.

If the grid is inclined the blocks can roll down into a storagecontainer.

BRIEF DESCRIPTION OF THE DRAWING One form of invention will now bedescribed by way of example with reference to the accompanying drawingwhich shows a diagrammatic cross-sectional side elevation of anice-making machine according to the invention.

DESCRIPTION OF THE INVENTlON A copper ice-making tube 1 is arrangedvertically within a secondary metal jacket 2 having an inlet 3 andoutlet 4. The jacket 2 is insulated by any readily available materials,e.g. polyurethane, to prevent heat losses into atmosphere, andcondensation. Spaced inside the ice-making tube 1 are cylindrical ringsor collars 6 and 7. The collars 6 are plastic (e.g. polypropylene), and

the collars 7 are made of highly conductive metal (e.g. copper). I

It will be seen from the drawing that the collars 6 are recessed overmost of their length to form closed annular air pockets 8 between thecollars and the tube 1. This has been found to provide very effectivethermal insulation. Collars 7 are placed between collars 6alternatively, and making good contact with inside of icemaking tube 1.

A deflector 9 at the top end of the tube 1 leads ice and waterdischarged from the tube 1 over an insulated header tank 10 having aninclined plastic grid 11 over the top. Beyond and below the grid 11 isan insulated container 12 for the formed. ice blocks. The header tank 10is replenished through a line 13 and a ball valve (not shown).'A lowpressure electric pump .P recirculates water from the header tank 10 tothe bottom of the tube 1 through insulated lines 14 and 15.

The jacket 2 forms the evaporator of a refrigeration system, refrigerantentering by the inlet 3 and leaving by the outlet 4. Provision is madefor flushing hot gas from the'condenser of the system through the jacketwhen the ice has been formed. This flushing can be initiated for exampleeither by a thermostat on the jacket 2 or an electronic conductivitydevice switch which measures the water flow through the deflectorarrangement 9. A further thermostat can be provided at the top of thecontainer 12 to shut the machine down when the container 12 is full.More than one of the tubes I having common water, refrigerant and hotgas supplies can be provided in one apparatus as desired.

In operation water is circulated upwards through the tube 1 and therefrigerant in the jacket 2 progressively cools it. When the watertemperature approaches freezing point ice forms in the tubes at the gapsbetween the collars 6 and progressively obstructs the tube 1 as shown bythe dotted lines 16 representing the ice surface. The blocks of iceformed thus have approximately conical recesses in each end, since iceis formed to a limited extent inside the ends of the collars 6. In otherwords, the blocks can be regarded as venturishaped conduits. The pumpcontinues to operate so when the hot gas is flushed through the jacket 2after the blocks are formed the blocks are released and driven out ofthe tube 1 and pass via the deflector arrangement 9, and the grid 11,into the container 12, any water which accompanies them falling throughthe grid "into the tank 10. The cycle is then repeated.

With two one inch diameter tubes, 2-3 ft. long, an Output of the orderof 50 lbs. per day may be achieved in the form of blocks about 1% inchlong assuming a minute cycle. Their venturi shape gives the advantagethat the blocks have a greater surface area and thus melt more quicklywhen placed in water. Another advantage is that the contents of the tubewould take several hours to freeze solid between the blocks and burstthe tube if the hot gas flush should fail.

What I claim is:

1. An ice-making apparatus comprising:

an open ended tube;

a jacket surrounding said tube and forming a space therewith;

heat conductive and heat insulating lining segments alternatelypositioned inside said tube in end-toend abutting relation to form aninternal duct having a smooth cylindrical surface comprised of alternatecontiguous heat conductive and heat insulating cylindrical areas; meansfor directing a flow of water through said duct;

and means for selectively supplying a flow of refrigerant and a flow ofgas at a temperature above the freezing point of water through saidspace. Y 2. An ice-making apparatus as claimed in claim 1, wherein saidwater flow directing means operates to pass water upwardly through saidduct.

3. An ice-making apparatus according to claim 1 in which the heatconductive segments are formed by lining collars of metal within thetube and the heat insulating segments are formed by lining collars ofheat insulating material within the tube alternating with the metalcollars, the ends of adjacent collars being in close abutment.

4. An ice-making apparatus according to claim 3, wherein the outersurfaces of the heat insulating collars are recessed over a part oftheir lengths to provide annular air spaces between the collars and thetube.

5. An ice-making apparatus according to claim 3, wherein the heatinsulating collars are made of a plastic material.

6. An ice-making apparatus according to claim I, wherein the jacket hasan inlet or outlet connectable into a refrigerating circuit to providethe flow of refrigerant through the spare and connectable to the circuitcondenser to provide the flow of gas through the spare.

7. An ice-making machine according to claim 1, including a waterre-circulating system wherein the water supplied to the duct is returnedafter flowing therethrough to the said flow directing means.

8. An ice-making apparatus according to claim 7, wherein the said flowdirecting means includes a tank to receive water returned from the duct,and means for replacing water lost from the re-circulation system asice.

1. An ice-making apparatus comprising: an open ended tube; a jacketsurrounding said tube and forming a space therewith; heat conductive andheat insulating lining segments alternately positioned inside said tubein end-to-end abutting relation to form an internal duct having a smoothcylindrical surface comprised of alternate contiguous heat conductiveand heat insulating cylindrical areas; means for directing a flow ofwater through said duct; and means for selectively supplying a flow ofrefrigerant and a flow of gas at a temperature above the freezing pointof water through said space.
 2. An ice-making apparatus as claimed inclaim 1, wherein said water flow directing means operates to pass waterupwardly through said duct.
 3. An ice-making apparatus according toclaim 1 in which the heat conductive segments are formed by liningcollars of metal within the tube and the heat insulating segments areformed by lining collars of heat insulating material within the tubealternating with the metal collars, the ends of adjacent collars beingin close abutment.
 4. An ice-making apparatus according to claim 3,wherein the outer surfaces of the heat insulating collars are recessedover a part of their lengths to provide annular air spaces between thecollars and the tube.
 5. An ice-making apparatus according to claim 3,wherein the heat insulating collars are made of a plastic material. 6.An ice-making apparatus according to claim 1, wherein the jacket has aninlet or outlet connectable into a refrigerating circuit to provide theflow of refrigerant through the spare and connectable to the circuitcondenser to provide the flow of gas through the spare.
 7. An ice-makingmachine according to claim 1, including a water re-circulating systemwherein the water supplied to the duct is returned after flowingtherethrough to the said flow directing means.
 8. An ice-makingapparatus according to claim 7, wherein the said flow directing meansincludes a tank to receive water returned from the duct, and means forreplacing water lost from the re-circulation system as ice.